1. Field
Some example embodiments relate to nitride semiconductor based power converting devices, and more particularly, to nitride semiconductor based power converting devices in which a power switching device and a passive device are formed on the same layer.
2. Description of the Related Art
Various power converting devices require devices for controlling flows of currents via ON/OFF switching, that is, power devices. The overall efficiency of a power converting device may depend on efficiency of a power device.
The most popular power devices currently being commercialized include a silicon (Si) based power metal oxide semiconductor field effect transistor (MOSFET) and an insulated gate bipolar transistor (IGBT). However, due to limits of material properties of silicon and limits in manufacturing processes, it is difficult to further improve efficiency of a Si-based power device. Recently, to resolve the problem, research is being conducted and developments are being made for improving power converting efficiency by applying Group III-V compound semiconductors to power devices. In relation thereto, a high electron mobility transistor (HEMT) using heterojunction of semiconductors is being spotlighted.
A HEMT includes semiconductor layers having different electric polarization characteristics. In a HEMT, a semiconductor layer having a relatively high electric polarization may induce 2-dimensional electron gas (2DEG) at an adjacent semiconductor layer, where the 2DEG may have high electron mobility.
A power converting device includes a HEMT and passive devices, such as a resistor, an inductor, and a capacitor. Structure of a power converting device may be simplified by integrating such passive devices together with a HEMT as a nitride semiconductor.